/*
 * Copyright (c) 2003, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.bundle.device;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Vector;

import org.osgi.framework.Bundle;
import org.osgi.framework.ServiceReference;
import org.osgi.service.device.Device;
import org.osgi.service.device.DriverLocator;
import org.osgi.service.device.Match;

public class MatchImpl
  implements Match
{
  static final int UNKNOWN = -1;

  private final Activator act;

  private final ServiceReference<?> dev;

  private final String id;

  private DriverRef ref;

  private int match;

  private Vector<DriverLocator> dls;

  private Bundle b;

  MatchImpl(Activator act, ServiceReference<?> dev, String id)
  {
    this.act = act;
    this.dev = dev;
    this.id = id;
    match = act.getCachedMatch(id, dev);
  }

  MatchImpl(Activator act, ServiceReference<?> dev, DriverRef dr)
  {
    this.act = act;
    this.dev = dev;
    id = dr.id;
    ref = dr;
    match = act.getCachedMatch(id, dev);
  }

  boolean equals(String id)
  {
    return this.id.equals(id);
  }

  boolean connect(DriverRef dr)
  {
    if (id.equals(dr.id) && (ref == dr || ref == null)) {
      ref = dr;
      return true;
    }
    return false;
  }

  int compare(MatchImpl m)
  {
    int cmp = getMatchValue() - m.getMatchValue();
    if (cmp == 0) {
      cmp = ref.ranking - m.ref.ranking;
    }
    if (cmp == 0) {
      cmp = ref.servid < m.ref.servid ? 1 : -1;
    }
    return cmp;
  }

  void addDriverLocator(DriverLocator dl)
  {
    if (dls == null) {
      dls = new Vector<DriverLocator>();
    }
    dls.addElement(dl);
  }

  Bundle getBundle()
  {
    return b;
  }

  private boolean load()
  {
    final String name = Activator.DYNAMIC_DRIVER_TAG + id;
    final Bundle[] ba = act.bc.getBundles();
    if (ba != null) {
      for (final Bundle element : ba) {
        if (name.equals(element.getLocation())) {
          return false;
        }
      }
    }
    if (dls != null) {
      for (int i = 0; i < dls.size(); i++) {
        if (load1(name, dls.elementAt(i))) {
          return true;
        }
      }
    } else {
      final List<DriverLocator> dls = new ArrayList<DriverLocator>();
      synchronized (act.locators) {
        dls.addAll(act.locators);
      }
      for (final DriverLocator dl : dls) {
        if (load1(name, dl)) {
          return true;
        }
      }
    }
    return false;
  }

  private boolean load1(String name, DriverLocator dl)
  {
    InputStream is = null;
    try {
      is = dl.loadDriver(id);
      b = act.installBundle(name, is);
      if (b != null) {
        return true;
      }
    } catch (final Exception e) {
    } finally {
      try {
        is.close();
      } catch (final Exception e1) {
      }
    }
    return false;
  }

  String attach()
      throws Exception
  {
    if (match > Device.MATCH_NONE && ref == null && b == null && load()) {
      return null;
    }
    match = Device.MATCH_NONE;
    return ref.drv.attach(dev);
  }

  public ServiceReference<?> getDriver()
  {
    return ref.sr;
  }

  public int getMatchValue()
  {
    if (match == UNKNOWN) {
      if (ref != null || b != null) {
        try {
          match = ref.drv.match(dev);
          act.putCachedMatch(id, dev, match);
        } catch (final Exception e) {
          match = Device.MATCH_NONE;
        }
      } else if (!load()) {
        match = Device.MATCH_NONE;
      }
    }
    return match;
  }
}
